| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for oxidizing a natural material having a flavonoid skeleton, and a method for dyeing hair using the oxidized material. <P>SOLUTION: The natural material having a flavonoid skeleton such as (+)- catechin is oxidized by oxygen gas in a mixed solvent of water and an alcohol under a basic condition to obtain a compound represented by general formula (2), (wherein, R<SB POS="POST">10</SB>, R<SB POS="POST">11</SB>, R<SB POS="POST">12</SB>and R<SB POS="POST">13</SB>indicate each independently a hydrogen atom, a hydroxy group or a methyl group; R<SB POS="POST">14</SB>indicates a hydrogen atom, a hydroxy group, a galloyl group or a saccharide; R<SB POS="POST">15</SB>indicates a hydrogen atom or a hydroxy group; and X indicates >CH<SB POS="POST">2</SB>, >C=O or >CHOH). <P>COPYRIGHT: (C)2013,JPO&INPIT |
